#define _CRT_SECURE_NO_WARNINGS 1

# include<iostream>
using namespace std;

typedef long long ll;

ll func(int n)
{
	if (n <= 1)
	{
		return 1;
	}
	else if (n == 2)
	{
		return 2;
	}
	else
	{
		return  func(n - 1) + func(n - 2);
	}
}

int main()
{
	int n = 0;
	cin >> n;
	cout << func(n) % 1000000007;
	return 0;
}

